Field of Invention
The present invention relates to a novel design and utility of fuel cells wherein a third electrode is interposed between the anode- and cathode electrodes of a conventional sandwich arrangement. The third electrode is in the present invention conductive to chemical species of the electrochemical couple and, therefore, permits their transport through the electrode material. It is also electrically conductive to electrons, thus allowing electrical current to flow as in a conventional solid metal electrode. However, when the third electrode is interposed between the anode and cathode of the fuel cell couple, as in a sandwich stack arrangement, its function is insulated from direct electrical contact with either the anode or cathode of the fuel cell couple by virtue of being embedded within the electrolyte. In that capacity and in conjunction with a voltage source, the third electrode functions as a reference or control electrode to regulate, manage, or monitor electrochemical processes at the anode or cathode.
The present invention teaches a novel concept in fuel cell design, operation, and utility that embodies an interposed third electrode between the anode and cathode of a conventional sandwich configuration. The third electrode is in the present invention conductive to chemical species of the electrochemical couple and, therefore, permits their transport through the electrode material. It is also electrically conductive to electrons, thus allowing electrical current to flow as in a conventional solid metal electrode. However, when the third electrode is interposed between the anode and cathode of the fuel cell couple, as in a sandwich stack arrangement, its function is insulated from direct electrical contact with either the anode or cathode of the fuel cell couple by virtue of being embedded within the electrolyte. In that capacity and in conjunction with a voltage or current source or an electrical measurement apparatus, the third electrode functions as a reference or control electrode to regulate, manage, or monitor electrochemical processes at the anode or cathode.
These and other objects, advantages and salient features of the invention are described in or are apparent from the following description of exemplary embodiments.